A) \[{{\cos }^{-1}}\left( \frac{n\lambda }{2d} \right)\]
B) \[{{\sin }^{-1}}\left( \frac{n\lambda }{2d} \right)\]
C) \[{{\sin }^{-1}}\left( \frac{n\lambda }{d} \right)\]
D) \[{{\tan }^{-1}}\left( \frac{n\lambda }{d} \right)\]
Correct Answer: B
Solution :
From the adjoining figure path difference between the beams- reflected from successive planes \[=AM+AN=2d\,\sin \theta \] For constructive interference \[2d\,\sin \theta =n\lambda \] \[\sin \theta =\frac{n\lambda }{2d}\] \[\theta ={{\sin }^{-1}}\left( \frac{n\lambda }{2d} \right)\]You need to login to perform this action.
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